Craig Whitmore wrote:
> ----- Original Message -----
> From: "Andy Smith" <andy@???>
> To: <exim-users@???>
> Sent: Sunday, January 07, 2007 9:08 PM
> Subject: Re: [exim] OT(?): SRS vs. SORBS sending mails with '<>' sender
>
> I've been talking about this on NANE. dsbl.org send new messages with <> as
> well (I've not found anyone else looking at my logs who do this).
>
> The RFC's don't say you cannot do it (unless someone can find the part which
> it says you cannot use <> in an initial message), but I don't think (IMHO)
> that its the intent of the RFC's to allow you to do this. (use <> in a new
> message) (not a DSN/NDN)
>
This is more or less suggested in 4.5.5 of RFC2821
All other types of messages (i.e., any message which is not required
by a standards-track RFC to have a null reverse-path) SHOULD be sent
with with a valid, non-null reverse-path.
And of course, as everybody knows:
3. SHOULD This word, or the adjective "RECOMMENDED", mean that
there may exist valid reasons in particular circumstances to
ignore a particular item, but the full implications must be
understood and carefully weighed before choosing a different
course.
So they don't strictly forbid it but they warn you that you will have
drawbacks. And drawbacks for this nowadays, just means your mail may be
blocked (somewhat forbidden too by RFC2821) or blackholed.